<template>
  <div>
    <div id="app">
      <div>
        <p>请选择你要购买的书籍</p>
        <ul>
          <li v-for="item in arr" :key="item.name">
            {{ item.name }} <button @click="item.count++">买书</button>
          </li>
        </ul>
        <table border="1" width="500" cellspacing="0">
          <tr v-for="(item, index) in arr" :key="item.name">
            <th>{{ index + 1 }}</th>
            <th>{{ item.name }}</th>
            <th>{{ item.price }}</th>
            <th>{{ item.count }}</th>
            <th>{{ item.price * item.count }}</th>
          </tr>
        </table>
        <p>总价格为:{{tot}}</p>
      </div>
    </div>
  </div>
</template>

<script>
export default {
  data() {
    return {
      arr: [
        {
          name: "水浒传",
          price: 107,
          count: 0,
        },
        {
          name: "西游记",
          price: 192,
          count: 0,
        },
        {
          name: "三国演义",
          price: 219,
          count: 0,
        },
        {
          name: "红楼梦",
          price: 178,
          count: 1,
        },
      ],
    };
  },
  computed: {
    tot() {
      return this.arr.reduce((t, c) => t + c.price * c.count, 0);
    },
  },
};
</script>

<style>
</style>